Human-rating certification

Human-rating certification is the certification of a spacecraft or launch vehicle as capable of transporting humans. NASA and the U.S. GAO now use "human-rating" when describing requirements for these systems; earlier equivalents were termed "man-rating".

In human spaceflight, a human-rating certification is the assurance that the space system accommodates human needs, effectively uses human capabilities, controls hazards with sufficient certainty to be considered safe for human operations, and provides, to the maximum extent practical, the capability to safely recover the crew from hazardous situations.[1] In the United States, the National Aeronautics and Space Administration (NASA) has published NASA Procedural Requirement NPR 8705.2C - Human Rating Requirements for Space Systems, defining the certification process and a set of technical requirements to be applied to its crewed space systems in addition to the standards and requirements that are mandatory for all of NASA's space flight programs.[1]

The NASA CCP human-rating standards require that the probability of a loss on ascent is no more than 1 in 500, and that the probability of a loss on descent is no more than 1 in 500, the overall mission loss risk, which includes vehicle risk from micrometeorites and orbital debris while in orbit for up to 210 days, is required to be no more than 1 in 270.[2] Maximum sustained G-loads are limited to three Earth-standard g's.[2]

^ abcChaikin, Andrew (2011-11-16). "Certified Safe: Planning to operate a taxi service for NASA astronauts? Here's what's required". Air & Space Smithsonian. Retrieved 2011-11-27. we've separated [the “loss of crew” criteria] into what you need for ascent and what you need for entry. For ascent it’s 1 in 500, and independently for entry it’s 1 in 500. ... The probability for the mission itself is 1 in 270, that is an overall number. That’s loss of crew for the entire mission profile, including ascent, on-orbit, and entry, the thing that drives the 1 in 270 is really micrometeorites and orbital debris ... whatever things that are in space that you can collide with. So that’s what drops that number down, because you’ve got to look at the 210 days, the fact that your heat shield or something might be exposed to whatever that debris is for that period of time. NASA looks at Loss of Vehicle the same as Loss of Crew. If the vehicle is damaged and it may not be detected prior to de-orbit, then you have loss of crew.'

1.
Spacecraft
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A spacecraft is a vehicle, or machine designed to fly in outer space. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, space colonization, planetary exploration, on a sub-orbital spaceflight, a spacecraft enters space and then returns to the surface, without having gone into an orbit. For orbital spaceflights, spacecraft enter closed orbits around the Earth or around other celestial bodies, robotic spacecraft used to support scientific research are space probes. Robotic spacecraft that remain in orbit around a body are artificial satellites. Only a handful of interstellar probes, such as Pioneer 10 and 11, Voyager 1 and 2, orbital spacecraft may be recoverable or not. By method of reentry to Earth they may be divided in non-winged space capsules, Sputnik 1 was the first artificial satellite. It was launched into an elliptical low Earth orbit by the Soviet Union on 4 October 1957, the launch ushered in new political, military, technological, and scientific developments, while the Sputnik launch was a single event, it marked the start of the Space Age. Apart from its value as a technological first, Sputnik 1 also helped to identify the upper atmospheric layers density and it also provided data on radio-signal distribution in the ionosphere. Pressurized nitrogen in the satellites false body provided the first opportunity for meteoroid detection, Sputnik 1 was launched during the International Geophysical Year from Site No. 1/5, at the 5th Tyuratam range, in Kazakh SSR. The satellite travelled at 29,000 kilometers per hour, taking 96.2 minutes to complete an orbit and this altitude is called the Kármán line. In particular, in the 1940s there were several test launches of the V-2 rocket, as of 2016, only three nations have flown manned spacecraft, USSR/Russia, USA, and China. The first manned spacecraft was Vostok 1, which carried Soviet cosmonaut Yuri Gagarin into space in 1961, there were five other manned missions which used a Vostok spacecraft. The second manned spacecraft was named Freedom 7, and it performed a sub-orbital spaceflight in 1961 carrying American astronaut Alan Shepard to an altitude of just over 187 kilometers, there were five other manned missions using Mercury spacecraft. Other Soviet manned spacecraft include the Voskhod, Soyuz, flown unmanned as Zond/L1, L3, TKS, China developed, but did not fly Shuguang, and is currently using Shenzhou. Except for the shuttle, all of the recoverable manned orbital spacecraft were space capsules. Manned space capsules The International Space Station, manned since November 2000, is a joint venture between Russia, the United States, Canada and several other countries, some reusable vehicles have been designed only for manned spaceflight, and these are often called spaceplanes. The first example of such was the North American X-15 spaceplane, the first reusable spacecraft, the X-15, was air-launched on a suborbital trajectory on July 19,1963. The first partially reusable spacecraft, a winged non-capsule, the Space Shuttle, was launched by the USA on the 20th anniversary of Yuri Gagarins flight

2.
Launch vehicle
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In spaceflight, a launch vehicle or carrier rocket is a rocket used to carry a payload from Earths surface into outer space. A launch system includes the launch vehicle, the launch pad, Earth orbital launch vehicles typically have at least two stages, and sometimes as many as four or more. Expendable launch vehicles are designed for one-time use and they usually separate from their payload and disintegrate during atmospheric reentry. In contrast, reusable vehicles are designed to be recovered intact. The Space Shuttle was a part of a vehicle with components used for multiple orbital spaceflights. SpaceX has developed a rocket launching system to successfully bring back a part—the first stage—of their Falcon 9 and launch it again. A fully reusable VTVL design is planned for all parts of the ITS launch vehicle, Launch vehicles are often classified by the amount of mass they can carry into orbit. For example, a Proton rocket can lift 22,000 kilograms into low Earth orbit, Launch vehicles are also characterized by their number of stages. Rockets with as many as five stages have been successfully launched, additionally, launch vehicles are very often supplied with boosters supplying high early thrust, normally burning with other engines. Boosters allow the engines to be smaller, reducing the burnout mass of later stages to allow larger payloads. Other frequently reported characteristics of vehicles are the launching nation or space agency. For example, the European Space Agency is responsible for the Ariane V, many launch vehicles are considered part of a historical line of vehicles of same or similar name, e. g. the Atlas V is the latest Atlas rocket. A small-lift launch vehicle is capable of lifting up to 2,000 kg of payload into low Earth orbit, a medium-lift launch vehicle is capable of lifting 2,000 to 20,000 kg of payload into LEO. A heavy-lift launch vehicle is capable of lifting 20,000 to 50,000 kg of payload into LEO, a super-heavy lift vehicle is capable of lifting more than 50,000 kg of payload into LEO. It refers to its 1,500 kg to LEO Vega launch vehicle as light lift, sounding rockets have long been used for brief, inexpensive unmanned space and microgravity experiments. Current human-rated suborbital launch vehicles include SpaceShipOne and the upcoming SpaceShipTwo, minimizing air drag requires a reasonably high ballistic coefficient, a ratio of length to diameter greater than ten. This generally results in a vehicle that is at least 20 m long. Leaving the atmosphere as early on in the flight as possible provides a velocity loss due to air drag of around 300 m/s, Launch vehicles of sufficient size are capable of launching payloads smaller than their orbital capability, to the Moon or beyond

3.
NASA
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President Dwight D. Eisenhower established NASA in 1958 with a distinctly civilian orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29,1958, disestablishing NASAs predecessor, the new agency became operational on October 1,1958. Since that time, most US space exploration efforts have led by NASA, including the Apollo Moon landing missions, the Skylab space station. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle, the agency is also responsible for the Launch Services Program which provides oversight of launch operations and countdown management for unmanned NASA launches. NASA shares data with various national and international such as from the Greenhouse Gases Observing Satellite. Since 2011, NASA has been criticized for low cost efficiency, from 1946, the National Advisory Committee for Aeronautics had been experimenting with rocket planes such as the supersonic Bell X-1. In the early 1950s, there was challenge to launch a satellite for the International Geophysical Year. An effort for this was the American Project Vanguard, after the Soviet launch of the worlds first artificial satellite on October 4,1957, the attention of the United States turned toward its own fledgling space efforts. This led to an agreement that a new federal agency based on NACA was needed to conduct all non-military activity in space. The Advanced Research Projects Agency was created in February 1958 to develop technology for military application. On July 29,1958, Eisenhower signed the National Aeronautics and Space Act, a NASA seal was approved by President Eisenhower in 1959. Elements of the Army Ballistic Missile Agency and the United States Naval Research Laboratory were incorporated into NASA, earlier research efforts within the US Air Force and many of ARPAs early space programs were also transferred to NASA. In December 1958, NASA gained control of the Jet Propulsion Laboratory, NASA has conducted many manned and unmanned spaceflight programs throughout its history. Some missions include both manned and unmanned aspects, such as the Galileo probe, which was deployed by astronauts in Earth orbit before being sent unmanned to Jupiter, the experimental rocket-powered aircraft programs started by NACA were extended by NASA as support for manned spaceflight. This was followed by a space capsule program, and in turn by a two-man capsule program. This goal was met in 1969 by the Apollo program, however, reduction of the perceived threat and changing political priorities almost immediately caused the termination of most of these plans. NASA turned its attention to an Apollo-derived temporary space laboratory, to date, NASA has launched a total of 166 manned space missions on rockets, and thirteen X-15 rocket flights above the USAF definition of spaceflight altitude,260,000 feet. The X-15 was an NACA experimental rocket-powered hypersonic research aircraft, developed in conjunction with the US Air Force, the design featured a slender fuselage with fairings along the side containing fuel and early computerized control systems

4.
Government Accountability Office
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The Government Accountability Office is a government agency that provides auditing, evaluation, and investigative services for the United States Congress. It is the audit institution of the federal government of the United States. The GAO was established as the General Accounting Office by the Budget and Accounting Act of 1921. reports recommendations looking to greater economy or efficiency in public expenditures. The name was changed in 2004 to Government Accountability Office by the GAO Human Capital Reform Act to better reflect the mission of the office, while most other countries have government entities similar to the GAO, their focus is primarily on conducting financial audits. The GAOs auditors conduct not only financial audits, but also engage in an assortment of performance audits. News media often draw attention to the GAOs work by publishing stories on the findings, members of Congress also frequently cite the GAOs work in statements to the press, congressional hearings, and floor debates on proposed legislation. The GAO is headed by the general of the U. S. a professional. The comptroller general is appointed by the president, by and with the advice and consent of the Senate, for a 15-year, the president selects a nominee from a list of at least three individuals recommended by an eight-member bipartisan, bicameral commission of congressional leaders. During such term, the general has standing to pursue litigation to compel access to federal agency information. The comptroller general may not be removed by the president, since 1921, there have been only seven comptrollers general, and no formal attempt has ever been made to remove a comptroller general. Labor-management relations became fractious during the 9-year tenure of the 7th comptroller general, on September 19,2007, GAO analysts voted by a margin of two to one, in a 75% turnout, to establish the first union in the GAOs 86-year history. The analysts voted to affiliate with the International Federation of Professional and Technical Engineers, there are more than 1,800 analysts in the GAO analysts bargaining unit, the local voted to name itself IFPTE Local 1921, in honor of the date of the GAOs establishment. On February 14,2008, the GAO analysts union approved its first-ever negotiated pay contract with management and these standards pertain to auditors professional qualifications, the quality of audit effort, and the characteristics of professional and meaningful audit reports. In 1992 the GAO hosted XIV INCOSAI, the triennial convention of the International Organization of Supreme Audit Institutions. Due to its nature of a specific meta-study, the Ig Nobel Prize motivation described it as a report about the report about reports about reports, GAO often produces highlights of its reports that serve as a statement for the record for various subcommittees of the United States Congress. Many reports are issued periodically and take a view of U. S. agencies operations. GAO also produces annual reports on key issues such as Duplication and Cost savings, the GAO prepares some 900 reports annually. GAO publishes reports and information relating to, inter alia, Each year the GAO issues a report on the financial statements of the United States Government

5.
Human spaceflight
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Human spaceflight is space travel with a crew or passengers aboard the spacecraft. The first human spaceflight was launched by the Soviet Union on 12 April 1961 as a part of the Vostok program, humans have been continuously present in space for 16 years and 153 days on the International Space Station. All early human spaceflight was crewed, where at least some of the passengers acted to carry out tasks of piloting or operating the spacecraft, after 2015, several human-capable spacecraft are being explicitly designed with the ability to operate autonomously. Since the retirement of the US Space Shuttle in 2011, only Russia and China have maintained human spaceflight capability with the Soyuz program, currently, all expeditions to the International Space Station use Soyuz vehicles, which remain attached to the station to allow quick return if needed. The United States is developing commercial crew transportation to facilitate access to ISS and low Earth orbit. While spaceflight has typically been an activity, commercial spaceflight has gradually been taking on a greater role. NASA has also played a role to stimulate private spaceflight through programs such as Commercial Orbital Transportation Services, the vehicles used for these services could then serve both NASA and potential commercial customers. Commercial resupply of ISS began two years after the retirement of the Shuttle, and commercial crew launches could begin by 2017 and these rockets were large enough to be adapted to carry the first artificial satellites into low Earth orbit. The USSR launched the first human in space, Yuri Gagarin into an orbit in Vostok 1 on a Vostok 3KA rocket. The US launched its first astronaut, Alan Shepard on a flight aboard Freedom 7 on a Mercury-Redstone rocket. Unlike Gagarin, Shepard manually controlled his spacecrafts attitude, and landed inside it, the first American in orbit was John Glenn aboard Friendship 7, launched 20 February 1962 on a Mercury-Atlas rocket. The USSR launched five more cosmonauts in Vostok capsules, including the first woman in space, the US launched a total of two astronauts in suborbital flight and four in orbit through 1963. US President John F. Kennedy raised the stakes of the Space Race by setting the goal of landing a man on the Moon, Geminis objective was to support Apollo by developing American orbital spaceflight experience and techniques to be used in the Moon mission. They were able to launch two orbital flights in 1964 and 1965 and achieved the first spacewalk, made by Alexei Leonov on Voskhod 2 on 8 March 1965, but Voskhod did not have Geminis capability to maneuver in orbit, and the program was terminated. In July 1969, Apollo 11 accomplished Kennedys goal by landing Neil Armstrong and Buzz Aldrin on the Moon 21 July, a total of six Apollo missions landed 12 men to walk on the Moon through 1972, half of which drove electric powered vehicles on the surface. The crew of Apollo 13, Lovell, Jack Swigert, and Fred Haise, survived a catastrophic in-flight spacecraft failure, meanwhile, the USSR secretly pursued human lunar orbiting and landing programs. On losing the Moon race, they concentrated on the development of stations, using the Soyuz as a ferry to take cosmonauts to. They started with a series of Salyut sortie stations from 1971 to 1986, after the Apollo program, the US launched the Skylab sortie space station in 1973, manning it for 171 days with three crews aboard Apollo spacecraft

6.
United States
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Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci

7.
Commercial Crew Development
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Commercial Crew Development is a multiphase, space technology development program that is funded by the U. S. government and administered by NASA. The program is intended to stimulate development of privately operated crew vehicles to be launched into low Earth orbit, the program is run by NASAs Commercial Crew and Cargo Program Office. NASA solicited a second set of CCdev proposals for development projects lasting for a maximum of 14 months in October of that year. In April 2011, NASA announced they would award up to nearly $270 million to four companies as they met their CCDev 2 objectives, NASA awarded Space Act Agreements for the third phase, named CCiCap, in August 2012, this would last until 2014. CCiCap is followed by CCtCap with Federal Acquisition Regulation Part 15 contracts, contracts were awarded to SpaceX and Boeing in September 2014. The NASA CCDev program followed Commercial Orbital Transportation Services, a program for developing commercial launch capability to send cargo into low Earth orbit. In December 2009, NASA provided the description of the CCDev program. Space Exploration policy with investments to stimulate the commercial space industry, the Commercial Crew & Cargo Program is applying Recovery Act funds to stimulate efforts within the private sector to develop and demonstrate human spaceflight capabilities. ARRA provided $400 million for space related activities. Of this amount, $50 million is to be used for the development of commercial crew space transportation concepts and this effort is known as CCDev. Contract funding for the CCDev program is different from traditional space industry contractor funding used on the Space Shuttle, Apollo, Gemini, contracts are issued for fixed-price, pay-for-performance milestones. The first flight of the CCDev program was planned to occur in 2015, administrator of NASA Charles Bolden attributed the delays to insufficient funding from Congress. Michael López-Alegría, President of the Commercial Spaceflight Federation, also attributed the delays in the program to funding problems, for the fiscal year 2011 budget, US$500 million was requested for the CCDev program, but Congress granted only $270 million. For the FY2012 budget, $850 million was requested but Congress approved a budget of $406 million, for the 2013 budget,830 million was requested but Congress approved $488 million. For the FY2014 budget, $821 million was requested, Congress approved $696 million, the last spaceflight gap was between 1975 and 1981, the current extended from 2011 to the first flight of either CCDev or SLS system. After the last flight of the STS in 2011 the clock began ticking on a U. S. spaceflight gap, the previous spaceflight gap was between 1975 and the first STS flight in April 1981, about six years. Unlike the last human spaceflight gap, the U. S. has bought seats on the still-active Russian launcher as part of their joint international project. U. S. Congress was aware such a gap could occur, at that time the first crewed flight of the planned Ares I launcher would not have occurred until 2015, and its first use at ISS until 2016

8.
International Space Station
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The International Space Station is a space station, or a habitable artificial satellite, in low Earth orbit. Its first component launched into orbit in 1998, and the ISS is now the largest man-made body in space, the ISS consists of pressurised modules, external trusses, solar arrays, and other components. ISS components have been launched by Russian Proton and Soyuz rockets, the ISS serves as a microgravity and space environment research laboratory in which crew members conduct experiments in biology, human biology, physics, astronomy, meteorology, and other fields. The station is suited for the testing of systems and equipment required for missions to the Moon. The ISS maintains an orbit with an altitude of between 330 and 435 km by means of reboost manoeuvres using the engines of the Zvezda module or visiting spacecraft and it completes 15.54 orbits per day. The ISS is the space station to be inhabited by crews, following the Soviet and later Russian Salyut, Almaz. The station has continuously occupied for 16 years and 156 days since the arrival of Expedition 1 on 2 November 2000. This is the longest continuous presence in low Earth orbit. It has been visited by astronauts, cosmonauts and space tourists from 17 different nations, Soyuz has very limited downmass capability. The ISS programme is a joint project among five participating space agencies, NASA, Roscosmos, JAXA, ESA, the ownership and use of the space station is established by intergovernmental treaties and agreements. The station is divided two sections, the Russian Orbital Segment and the United States Orbital Segment, which is shared by many nations. As of January 2014, the American portion of ISS is being funded until 2024, Roscosmos has endorsed the continued operation of ISS through 2024 but has proposed using elements of the Russian Orbital Segment to construct a new Russian space station called OPSEK. On 28 March 2015, Russian sources announced that Roscosmos and NASA had agreed to collaborate on the development of a replacement for the current ISS. NASA later issued a statement expressing thanks for Russias interest in future co-operation in space exploration. According to the original Memorandum of Understanding between NASA and Rosaviakosmos, the International Space Station was intended to be a laboratory, observatory and factory in low Earth orbit. It was also planned to provide transportation, maintenance, and act as a base for possible future missions to the Moon, Mars. In the 2010 United States National Space Policy, the ISS was given roles of serving commercial, diplomatic. The ISS provides a platform to conduct scientific research, the ISS simplifies individual experiments by eliminating the need for separate rocket launches and research staff

9.
Probability
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Probability is the measure of the likelihood that an event will occur. Probability is quantified as a number between 0 and 1, the higher the probability of an event, the more certain that the event will occur. A simple example is the tossing of a fair coin, since the coin is unbiased, the two outcomes are both equally probable, the probability of head equals the probability of tail. Since no other outcomes are possible, the probability is 1/2 and this type of probability is also called a priori probability. Probability theory is used to describe the underlying mechanics and regularities of complex systems. For example, tossing a coin twice will yield head-head, head-tail, tail-head. The probability of getting an outcome of head-head is 1 out of 4 outcomes or 1/4 or 0.25 and this interpretation considers probability to be the relative frequency in the long run of outcomes. A modification of this is propensity probability, which interprets probability as the tendency of some experiment to yield a certain outcome, subjectivists assign numbers per subjective probability, i. e. as a degree of belief. The degree of belief has been interpreted as, the price at which you would buy or sell a bet that pays 1 unit of utility if E,0 if not E. The most popular version of subjective probability is Bayesian probability, which includes expert knowledge as well as data to produce probabilities. The expert knowledge is represented by some prior probability distribution and these data are incorporated in a likelihood function. The product of the prior and the likelihood, normalized, results in a probability distribution that incorporates all the information known to date. The scientific study of probability is a development of mathematics. Gambling shows that there has been an interest in quantifying the ideas of probability for millennia, there are reasons of course, for the slow development of the mathematics of probability. Whereas games of chance provided the impetus for the study of probability. According to Richard Jeffrey, Before the middle of the century, the term probable meant approvable. A probable action or opinion was one such as people would undertake or hold. However, in legal contexts especially, probable could also apply to propositions for which there was good evidence, the sixteenth century Italian polymath Gerolamo Cardano demonstrated the efficacy of defining odds as the ratio of favourable to unfavourable outcomes

10.
Micrometeorite
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A micrometeorite is an extraterrestrial particle, ranging in size from 50 µm to 2 mm, collected on the Earths surface. Micrometeorites are micrometeoroids which have survived entry through the Earths atmosphere and they differ from meteorites in being smaller, more plentiful and different in composition and are a subset of cosmic dust, which also includes the smaller interplanetary dust particles. Micrometeorites enter the Earths atmosphere with high velocities and undergo heating through atmospheric friction and compression, individual micrometeorites weigh between 10−9 and 10−4 g and collectively contribute most of the extraterrestrial material that has come to the present day Earth. Fred Lawrence Whipple first coined the term micro-meteorite to describe dust-sized objects that fall to the Earth, sometimes meteoroids and micrometeoroids entering the Earths atmosphere are visible as meteors or shooting stars, whether or not they reach the ground and survive as meteorites and micrometorites. Classification is based on composition and degree of heating, the extraterrestrial origins of micrometeorites are determined by microanalyses that show that, The metal they contain is similar to that found in meteorites. Some have wüstite, an iron oxide found in meteorite fusion crusts. Their silicate minerals have major and trace elements ratios similar to those in meteorites, an estimated 30,000 ±20,000 tonnes per year of cosmic dust enters the upper atmosphere each year of which less than 10% is estimated to reach the surface as particles. Micrometeorites have been collected from sediments, sedimentary rocks and polar sediments, they are currently collected primarily from polar snow. Because of their low concentrations on the Earths surface, MMs are sought in environments that concentrate these materials relative to terrestrial particles, melted micrometeorites were first collected from deep-sea sediments during the 1873 to 1876 expedition of the HMS Challenger. In 1891, Murray and Renard found two groups, first, black magnetic spherules, with or without a nucleus, second, brown-coloured spherules resembling chondres. The spherules were most abundant in slowly accumulating sediments, particularly red clays deposited below the carbonate compensation depth, in addition to those spheres with Fe-Ni metal cores, some spherules larger than 300 µm contain a core of elements from the platinum group. Since the first collection of the HMS Challenger, cosmic spherules have been recovered from ocean sediments using cores, box cores, clamshell grabbers, and magnetic sleds. Among these a magnetic sled, called the Cosmic Muck Rake, the oldest MMs are totally altered iron spherules found in 140- to 180-million-year-old hardgrounds. Amateur collectors may find micrometeorites in areas where dirt and dust from an area has been concentrated. Modern classification of meteorites and micrometeorites is complex, the 2007 review paper of Krot et al. summarizes modern meteorite taxonomy, linking individual micrometeorites to meteorite classification groups requires a comparison of their elemental, isotopic and textural characteristics. Whereas most meteorites likely originate from asteroids, the makeup of micrometeorites suggests that most originate from comets. Fewer than 1% of MMs are achondritic and are similar to HED meteorites, most MMs are compositionally similar to carbonaceous chondrites, whereas approximately 3% of meteorites are of this type. The dominance of carbonaceous chondrite-like MMs and their low abundance in meteorite collections suggests that most MMs derive from sources different than those for most meteorites, since most meteorites probably derive from asteroids, an alternative source for MMs might be comets

11.
Space debris
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As of December 2016 there were 5 satellite collisions with space waste. As of 5 July 2016, the United States Strategic Command tracked a total of 17,852 artificial objects in orbit about the Earth, including 1,419 operational satellites. For comparison, the International Space Station orbits in the 300–400 kilometres range, the ISS has Whipple shielding, however known debris with a collision chance over 1/10000 are avoided by maneuvering the station. The Kessler syndrome, a chain reaction of collisions exponentially increasing the amount of debris, has been hypothesized to ensue beyond a critical density. This could affect useful polar-orbiting bands, increases the cost of protection for spacecraft missions, whether it is already underway is debated. The measurement, mitigation and potential removal of debris are conducted by participants in the space industry. During the 1970s and 1980s, the Soviet Union launched a number of naval surveillance satellites as part of their RORSAT program, the satellites were equipped with a BES-5 nuclear reactor to power their radar systems. Although the satellites were normally boosted into a graveyard orbit at end of life. Satellites which were disposed of had an estimated eight-percent probability of puncture, the coolant freezes into droplets of solid sodium-potassium alloy, forming additional debris. As of 2009,19,000 debris over 5 cm were tracked, there are over 170 million pieces of debris smaller than 1 cm as of July 2013. There are approximately 670,000 pieces from one to ten cm, the current count of large debris is 29,000. The technical measurement cutoff is ~3 mm, over 98 percent of the 1,900 tons of debris in low Earth orbit was accounted for by about 1,500 objects, each over 100 kg. Total mass is mostly constant despite addition of smaller objects. Using a 2008 figure of 8,500 known items, it is estimated at 5,500 t, in LEO there are few universal orbits which keep spacecraft in particular rings. The closest are sun-synchronous orbits that keep a constant angle between the Sun and the plane, they are polar, meaning they cross over the polar regions. LEO satellites orbit in many planes, up to 15 times a day, orbits are further changed by perturbations, and collisions can occur from any direction. These can cross other orbits and lead to a cascade effect, a large-enough collision could make low Earth orbit impassable. Manned missions are mostly at 400 km and below, where air drag helps clear zones of fragments, atmospheric expansion as a result of space weather raises the critical altitude by increasing drag, in the 90s, it was a factor in reduced debris density

12.
G-force
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The g-force is a measurement of the type of acceleration that causes a perception of weight. Despite the name, it is incorrect to consider g-force a fundamental force, since g-force accelerations indirectly produce weight, any g-force can be described as a weight per unit mass. The types of forces involved are transmitted through objects by interior mechanical stresses, the g-force acceleration is the cause of an objects acceleration in relation to free-fall. The g-force acceleration experienced by an object is due to the sum of all non-gravitational. In practice, as noted, these are surface-contact forces between objects, such forces cause stresses and strains on objects, since they must be transmitted from an object surface. Because of these strains, large g-forces may be destructive, gravitation acting alone does not produce a g-force, even though g-forces are expressed in multiples of the acceleration of a standard gravity. Thus, the gravitational acceleration at the Earths surface produces g-force only indirectly. These mechanical forces actually produce the g-force acceleration on a mass, for example, the 1 g force on an object sitting on the Earths surface is caused by mechanical force exerted in the upward direction by the ground, keeping the object from going into free-fall. The upward contact-force from the ground ensures that an object at rest on the Earths surface is accelerating relative to the free-fall condition, stress inside the object is ensured from the fact that the ground contact forces are transmitted only from the point of contact with the ground. Objects allowed to free-fall in an inertial trajectory under the influence of only, feel no g-force acceleration. This is demonstrated by the conditions inside a freely falling elevator falling toward the Earths center. These are examples of coordinate acceleration without a sensation of weight, the experience of no g-force, however it is produced, is synonymous with weightlessness. An example here is a rocket in space, in which simple changes in velocity are produced by the engines. The unit of measure of acceleration in the International System of Units is m/s2, however, to distinguish acceleration relative to free-fall from simple acceleration, the unit g is often used. One g is the due to gravity at the Earths surface and is the standard gravity, defined as 9.80665 metres per second squared. Note that the definition does not vary with location—the g-force when standing on the moon is about 0.181 g. The unit g is not one of the SI units, which uses g for gram, also g should not be confused with G, which is the standard symbol for the gravitational constant. For example, it is said an F-16 fighter jet is able to sustain up to 9 Gs for a limited time

13.
Gravity of Earth
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The gravity of Earth, which is denoted by g, refers to the acceleration that is imparted to objects due to the distribution of mass within the Earth. In SI units this acceleration is measured in metres per second squared or equivalently in newtons per kilogram and this quantity is sometimes referred to informally as little g. The precise strength of Earths gravity varies depending on location, the nominal average value at the Earths surface, known as standard gravity is, by definition,9.80665 m/s2. This quantity is denoted variously as gn, ge, g0, gee, the weight of an object on the Earths surface is the downwards force on that object, given by Newtons second law of motion, or F = ma. Gravitational acceleration contributes to the acceleration, but other factors, such as the rotation of the Earth, also contribute. The Earth is not spherically symmetric, but is slightly flatter at the poles while bulging at the Equator, there are consequently slight deviations in both the magnitude and direction of gravity across its surface. The net force as measured by a scale and plumb bob is called effective gravity or apparent gravity, effective gravity includes other factors that affect the net force. These factors vary and include such as centrifugal force at the surface from the Earths rotation. Effective gravity on the Earths surface varies by around 0. 7%, in large cities, it ranges from 9.766 in Kuala Lumpur, Mexico City, and Singapore to 9.825 in Oslo and Helsinki. The surface of the Earth is rotating, so it is not a frame of reference. At latitudes nearer the Equator, the centrifugal force produced by Earths rotation is larger than at polar latitudes. This counteracts the Earths gravity to a small degree – up to a maximum of 0. 3% at the Equator –, the same two factors influence the direction of the effective gravity. Gravity decreases with altitude as one rises above the Earths surface because greater altitude means greater distance from the Earths centre, all other things being equal, an increase in altitude from sea level to 9,000 metres causes a weight decrease of about 0. 29%. It is a misconception that astronauts in orbit are weightless because they have flown high enough to escape the Earths gravity. In fact, at an altitude of 400 kilometres, equivalent to an orbit of the Space Shuttle. Weightlessness actually occurs because orbiting objects are in free-fall, the effect of ground elevation depends on the density of the ground. A person flying at 30000 ft above sea level over mountains will feel more gravity than someone at the same elevation, however, a person standing on the earths surface feels less gravity when the elevation is higher. The following formula approximates the Earths gravity variation with altitude, g h = g 02 Where gh is the acceleration at height h above sea level

14.
Space Shuttle
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The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated by the U. S. National Aeronautics and Space Administration, as part of the Space Shuttle program. Its official program name was Space Transportation System, taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development, the first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982. Five complete Shuttle systems were built and used on a total of 135 missions from 1981 to 2011, the Shuttle fleets total mission time was 1322 days,19 hours,21 minutes and 23 seconds. Shuttle components included the Orbiter Vehicle, a pair of solid rocket boosters. The Shuttle was launched vertically, like a rocket, with the two SRBs operating in parallel with the OVs three main engines, which were fueled from the ET. The SRBs were jettisoned before the vehicle reached orbit, and the ET was jettisoned just before orbit insertion, at the conclusion of the mission, the orbiter fired its OMS to de-orbit and re-enter the atmosphere. The orbiter then glided as a spaceplane to a landing, usually at the Shuttle Landing Facility of KSC or Rogers Dry Lake in Edwards Air Force Base. After landing at Edwards, the orbiter was back to the KSC on the Shuttle Carrier Aircraft. The first orbiter, Enterprise, was built in 1976 for use in Approach, four fully operational orbiters were initially built, Columbia, Challenger, Discovery, and Atlantis. Of these, two were lost in accidents, Challenger in 1986 and Columbia in 2003, with a total of fourteen astronauts killed. A fifth operational orbiter, Endeavour, was built in 1991 to replace Challenger, the Space Shuttle was retired from service upon the conclusion of Atlantiss final flight on July 21,2011. Nixons post-Apollo NASA budgeting withdrew support of all components except the Shuttle. The vehicle consisted of a spaceplane for orbit and re-entry, fueled by liquid hydrogen and liquid oxygen tanks. The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982, all launched from the Kennedy Space Center, Florida. The system was retired from service in 2011 after 135 missions, the program ended after Atlantis landed at the Kennedy Space Center on July 21,2011. Major missions included launching numerous satellites and interplanetary probes, conducting space science experiments, the first orbiter vehicle, named Enterprise, was built for the initial Approach and Landing Tests phase and lacked engines, heat shielding, and other equipment necessary for orbital flight. A total of five operational orbiters were built, and of these and it was used for orbital space missions by NASA, the US Department of Defense, the European Space Agency, Japan, and Germany. The United States funded Shuttle development and operations except for the Spacelab modules used on D1, sL-J was partially funded by Japan

15.
Space Shuttle Challenger disaster
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The spacecraft disintegrated over the Atlantic Ocean, off the coast of Cape Canaveral, Florida, at 11,39 EST. Disintegration of the vehicle began after an O-ring seal in its solid rocket booster failed at liftoff. The O-ring was not designed to fly under unusually cold conditions as in this launch and this led to the separation of the right-hand SRBs aft field joint attachment and the structural failure of the external tank. Aerodynamic forces broke up the orbiter, the crew compartment and many other vehicle fragments were eventually recovered from the ocean floor after a lengthy search and recovery operation. The exact timing of the death of the crew is unknown, the shuttle had no escape system, and the impact of the crew compartment with the ocean surface was too violent to be survivable. The Rogers Commission found NASAs organizational culture and decision-making processes had been key contributing factors to the accident, NASA managers had known since 1977 that contractor Morton Thiokols design of the SRBs contained a potentially catastrophic flaw in the O-rings, but they had failed to address this problem properly. Approximately 17 percent of Americans witnessed the launch live because of the presence of Payload Specialist Christa McAuliffe, media coverage of the accident was extensive, one study reported that 85 percent of Americans surveyed had heard the news within an hour of the accident. The Challenger disaster has been used as a study in many discussions of engineering safety. Each of the Space Shuttles two Solid Rocket Boosters was constructed of seven sections, six of which were joined in pairs at the factory. For each flight, the four resulting segments were then assembled in the Vehicle Assembly Building at Kennedy Space Center, the factory joints were sealed with asbestos-silica insulation applied over the joint, while each field joint was sealed with two rubber O-rings. During the Space Shuttle design process, a McDonnell Douglas report in September 1971 discussed the safety record of solid rockets, while a safe abort was possible after most types of failures, one was especially dangerous, a burnthrough by hot gases of the rockets casing. The report stated that if burnthrough occurs adjacent to tank or orbiter, timely sensing may not be feasible and abort not possible, Morton Thiokol was the contractor responsible for the construction and maintenance of the shuttles SRBs. This phenomenon, known as joint rotation, caused a drop in air pressure. This made it possible for combustion gases to erode the O-rings, in the event of widespread erosion, a flame path could develop, causing the joint to burst—which would have destroyed the booster and the shuttle. Evidence of serious O-ring erosion was present as early as the space shuttle mission, STS-2. Contrary to NASA regulations, the Marshall Center did not report this problem to senior management at NASA, by 1985, Marshall and Thiokol realized that they had a potentially catastrophic problem on their hands. They began the process of redesigning the joint with three inches of steel around the tang. This tang would grip the inner face of the joint and prevent it from rotating and they did not call for a halt to shuttle flights until the joints could be redesigned, but rather treated the problem as an acceptable flight risk

16.
Space Shuttle Columbia disaster
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On February 1,2003, the Space Shuttle Columbia disintegrated upon reentering Earths atmosphere, killing all seven crew members. The disaster was the tragedy in the Space Shuttle program after Space Shuttle Challenger in 1986. During the launch of STS-107, Columbias 28th mission, a piece of foam broke off from the Space Shuttle external tank. A few previous shuttle launches had seen damage ranging from minor to major from foam shedding, NASA managers limited the investigation, reasoning that the crew could not have fixed the problem if it had been confirmed. After the disaster, Space Shuttle flight operations were suspended for more than two years, as they had been after the Challenger disaster. Commander, Rick D. Husband, a U. S. Air Force colonel and mechanical engineer, payload Commander, Michael P. Anderson, a U. S. Air Force lieutenant colonel, physicist, and mission specialist who was in charge of the science mission. Payload Specialist, Ilan Ramon, a colonel in the Israeli Air Force, Mission Specialist, Kalpana Chawla, aerospace engineer who was on her second space mission. Mission Specialist, David M. Brown, a U. S. Navy captain trained as an aviator, Mission Specialist, Laurel Blair Salton Clark, a U. S. Navy captain and flight surgeon. The shuttles main fuel tank is covered in thermal insulation foam intended to prevent ice from forming when the tank is full of liquid hydrogen and oxygen, such ice could damage the shuttle if shed during lift-off. Mission STS-107 was the 113th Space Shuttle launch, planned to begin on January 11,2001, the mission was delayed 18 times and eventually launched on January 16,2003, following STS-113. About 82 seconds after launch from Kennedy Space Centers LC-39-A, a piece of foam broke off from the External Tank. At the time of the strike, the orbiter was at an altitude of about 66,000 feet. The Left Bipod Foam Ramp is an approximately three-foot long aerodynamic component made entirely of foam, the foam, not normally considered to be a structural material, is required to bear some aerodynamic loads. Because of these requirements, the casting-in-place and curing of the ramps may be performed only by a senior technician. Bipod Ramp insulation had been observed falling off, in whole or in part, on four flights, STS-7, STS-32, STS-50. All affected shuttle missions completed successfully, NASA management came to refer to this phenomenon as foam shedding. This phenomenon was termed normalization of deviance by sociologist Diane Vaughan in her book on the Challenger launch decision process. As it happened, STS-112 had been the first flight with the ET Cam, after STS-112, NASA leaders analyzed the situation and decided to press ahead under the justification that he ET is safe to fly with no new concerns of further foam strikes

17.
United Launch Alliance
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United Launch Alliance is a joint venture of Lockheed Martin Space Systems and Boeing Defense, Space & Security. ULA was formed in December 2006 by combining the teams at these companies which provide spacecraft launch services to the government of the United States, U. S. government launch customers include both the Department of Defense and NASA, as well as other organizations. With ULA, Lockheed and Boeing held a monopoly on military launches for more than a decade, until the US Air Force awarded a GPS satellite contract to SpaceX in 2016. Beginning in October 2014, ULA announced that they intended to undertake a substantial restructuring of the company, its products and processes, ULA is planning on building a new rocket that will be a successor to the Atlas V, using a new rocket engine on the first stage. In April 2015, they unveiled the new vehicle as the Vulcan, Boeing and Lockheed Martin announced their intent to form the United Launch Alliance joint venture on May 2,2005. ULA had a peak of seven space launch facilities during 2005–2011 and it announced a consolidation to five in 2008 with the intent to close two of its three Delta II pads, and closed the two-pad launch complex at Cape Canaveral after its final Delta II launch in 2011. SpaceX challenged the United States antitrust law legality of the launch services monopoly on October 23,2005, SpaceX was interested in competing for government launch contracts with the Falcon 9 rocket. The FTC gave their anti-trust clearance on October 3,2006, in November 2010, United Launch Alliance was selected by NASA for consideration for potential contract awards for heavy lift launch vehicle system concepts, and propulsion technologies. It was announced in August 2014 that Michael Gass, ULA CEO since ULA was founded in 2006, would step down immediately, ULA announced in February 2015 that they are considering undertaking domestic production of the Russian RD-180 engine at the Decatur, Alabama rocket stage manufacturing facility. The US-manufactured engines would be used only for government civil or commercial launches, Aerojet Rocketdyne Holdings Inc submitted a $2 billion offer to purchase the joint venture on September 8,2015. According to industry officials, the bid, if successful, would create a unified leadership for the company. On September 16,2015, spokesperson Todd Blecher for joint owner Boeing commented that Aerojet Rocketdynes bid was never seriously entertained and rejected the offer, in October 2014, ULA announced a major restructuring of processes and workforce in order to decrease launch costs by half. One of the reasons given for the restructuring and new cost reduction goals was competition from SpaceX. ULA intends to have preliminary design ideas in place for a blending of the Atlas V and Delta IV technology by the end of 2014, to build a successor that will allow them to cut launch costs in half. CEO Tory Bruno stated in November 2014 that he intends to transform the company and reorganize it to make it more agile, and establish new business models to adapt to the new environment. These changes will lead to improvements in how ULA interacts with its customers, ULA intends to shrink the number of company launch pads from six in 2008 and five in 2015 to only two by 2021 as they ramp down the legacy Atlas V and Delta IV launch vehicles. In May 2015, ULA announced it would decrease its executive ranks by 30 percent in December 2015, the management layoffs are the beginning of a major reorganization and redesign as ULA endeavours to slash costs and hunt out new customers to ensure continued growth despite the rise of SpaceX. In May 2015, ULA stated that it would go out of business unless it won commercial and civil satellite launch orders to offset an expected slump in U. S. military and spy launches

18.
American Institute of Aeronautics and Astronautics
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The American Institute of Aeronautics and Astronautics is a professional society for the field of aerospace engineering. AIAA is the U. S. representative on the International Astronautical Federation, as of 2015, AIAA has more than 30,000 members among aerospace professionals worldwide, although the majority are American and/or live in the United States. As a major activity AIAA currently publishes several technical journals, the AIAA Journal is published on a monthly basis and serves as the flagship journal of the society. In January 2015 the Journal of Guidance, Control, and Dynamics became the second AIAA journal published on a monthly basis, AIAA also produces several series of technical books ranging from education to progress in advanced research topics. AIAA formed the AIAA Foundation to devote more attention and more resources to the education of both practicing and future aerospace professionals, the AIAA Foundation funds numerous scholarships for both undergraduate and graduate students. Undergraduate scholarships range from $2,000 to $2,500, graduate scholarships are $5,000 or $10,000. AIAA currently has over 6,500 student members in 160 active student branches, the student branches host annual conferences AIAAs highest award for astronautics. It was endowed by Mrs. Robert Goddard in commemoration of her husbands pioneering efforts led to the development of the fields of astronautics. AIAAs highest award for science and engineering. It is named for Dr. Sylvanus A. Reed pioneer of the use of metal in propellor blades, initiated by the founder of Zonatech and given every four years for those who have contributed significantly to the area of aeroelasticity. It is named after famous aeroelastician Prof. Holt Ashley who served as a faculty member at MIT, selection is monitored/coordinated by the awards sub-committee of AIAA Structural Dynamics technical group. Dryden Lectureship in Research, named for Dr. Hugh L. Dryden Durand Lectureship, the Technical Award is presented for a significant accomplishment in developing or using technology that is required for missile systems. The Technical and Management award are presently alternatively at the biannual Missile Sciences Conference, thus, the awards are presented once every four years. The 2008 Technical Award winner was Ernest Ohlmeyer, the award is administered by the AIAA Missile Systems Technical Committee. This award is presented annually to outstanding achievement in the development or application of rocket propulsion systems. The award honors James Hart Wyld, AIAA hosts many conferences and smaller events throughout the year. The largest of those is the AIAA Science and Technology Forum, others include AIAA Aviation and Aeronautics Forum and Exposition, AIAA Propulsion and Energy Forum and Exposition, and AIAA Space and Astronautics Forum and Exposition. National Association of Rocketry Tripoli Rocketry Association International Astronautical Federation SpaceOps Official website

19.
Delta IV
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Delta IV is an expendable launch system in the Delta rocket family. The rockets main components are designed by Boeings Defense, Space & Security division and built in the United Launch Alliance facility in Decatur, final assembly is completed at the launch site by ULA. The rockets were designed to launch payloads into orbit for the United States Air Force Evolved Expendable Launch Vehicle program, Delta IV rockets are available in five versions, Medium, Medium+, Medium+, Medium+, and Heavy, to cover a range of payload size and weight. Delta IV was primarily designed to satisfy the needs of the U. S. military, the rockets are assembled at the Horizontal Integration Facility for launches from SLC-37B at Cape Canaveral, and in a similar facility for launches from SLC-6 at Vandenberg Air Force Base. While the Delta-IV retains the name of the Delta family of rockets, a primary change in the design is that the first stage uses liquid hydrogen fuel, rather than the kerosene fuel of earlier Delta boosters, and thus used a new engine, the Rocketdyne RS-68s. The Delta IV entered the space launch market when global capacity was already higher than demand. Furthermore, as a design it has had difficulty finding a market in commercial launches. In 2003, Boeing pulled the Delta IV from the market, citing low demand. In 2005, Boeing stated that it sought to return the Delta IV to commercial service, all of Delta IVs launches, with the exception of its debut launch carrying the Eutelsat W5 commercial communications satellite, were paid for by the US government. In 2015, ULA stated that a Delta IV Heavy is sold for nearly $400 million, the United States Air Force funds Delta IV engineering, integration, and infrastructure through contracts with Boeing Launch Services. On August 8,2008 the USAF Space and Missile Systems Center increased the cost plus award fee contract with BLS for $1.656 billion to extend the period of performance through the end of FY09, in addition a $557.1 million option was added to cover FY10. In March 2015, ULA announced plans to phase out all Delta IV launchers except the Delta IV Heavy by 2018, the Delta IV will be largely replaced by the Atlas V. On October 4,2012, a Delta IV M+ experienced an anomaly in the upper stages RL10-B-2 engine which resulted in lower than expected thrust. By December 2012 ULA had determined the cause of the anomaly to be a fuel leak, after two more successful launches, further investigation led to the delay of Delta flight 365 with the GPS IIF-5 satellite. Originally scheduled to launch in October 2013, the vehicle lifted off on February 21,2014, the Vulcan rocket is planned to replace the Atlas V and Delta IV rockets. Vulcan is projected to enter service by 2019, using the Blue Origin BE-4 methane-fuelled rocket engine. The Delta IV Heavy and Atlas V are expected to stay in service for a few years after Vulcans inaugural launch, and the Heavy is expected to be discontinued in the late 2020s. The first stage of a Delta IV consists of one, or in the Heavy variety three, Common Booster Cores powered by a Rocketdyne RS-68 engine, which burns liquid hydrogen and liquid oxygen

20.
Atlas V
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Atlas V is an active expendable launch system in the Atlas rocket family. Atlas V was formerly operated by Lockheed Martin, and is now operated by the Lockheed Martin-Boeing joint venture United Launch Alliance, the RD-180 engines are provided by RD Amross, while Aerojet Rocketdyne provides both the RL10 engines and the strap-on boosters used in some configurations. The standard payload fairing sizes are 4 or 5 meters in diameter, fairings sizes as large as 7.2 m in diameter and up to 32.3 m in length have been considered. The rocket is assembled in Decatur, Alabama and Harlingen, Texas, the Atlas V was developed by Lockheed Martin Commercial Launch Services as part of the US Air Force Evolved Expendable Launch Vehicle program and made its inaugural flight on August 21,2002. The vehicle operates out of Space Launch Complex 41 at Cape Canaveral Air Force Station, Lockheed Martin Commercial Launch Services continues to market the Atlas V to commercial customers worldwide. The Atlas V first stage, the Common Core Booster, is 12.5 ft in diameter and 106.6 ft in length and it is powered by a single Russian RD-180 main engine burning 627,105 lb of liquid oxygen and RP-1. The booster operates for four minutes, providing about 4 meganewtons of thrust. Thrust can be augmented with up to five Aerojet strap-on solid rocket boosters, the Atlas V is the newest member of the Atlas family. Compared to the Atlas III vehicle, there are numerous changes, compared to the Atlas II, the first stage is a near-redesign. The 1.5 staging technique was dropped on the Atlas III, the RD-180 features a dual-combustion chamber, dual-nozzle design and is fueled by a kerosene/liquid oxygen mixture. The main-stage diameter increased from 10 feet to 12.5 feet, as with the Atlas III, the different mixture ratio of the engine called for a larger oxygen tank compared to Western engines and stages. The first stage no longer use stainless steel monocoque balloon construction. The tanks are aluminum and are structurally stable when unpressurized. Use of aluminum, with a thermal conductivity than stainless steel. The tanks are covered in a polyurethane-based layer, accommodation points for parallel stages, both smaller solids and identical liquids, are built into first stage structures. The Centaur upper stage uses a pressure stabilized propellant tank design, the inertial navigation unit located on the Centaur provides guidance and navigation for both the Atlas and Centaur, and controls both Atlas and Centaur tank pressures and propellant use. The Centaur engines are capable of multiple in-space starts, making possible insertion into low Earth parking orbit, followed by a coast period, a subsequent third burn following a multi-hour coast can permit direct injection of payloads into geostationary orbit. The standard payload fairing sizes are 4 or 5 meters in diameter, the 4. 2-meter fairing, originally designed for the Atlas II booster, comes in three different lengths, the original 9-meter high version, as well as fairings 10 meters and 11 meters high

21.
Federal Aviation Administration
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The Federal Aviation Administration of the United States is a national authority with powers to regulate all aspects of civil aviation. The FAAs roles include, Regulating U. S, each LOB has a specific role within the FAA. Airports — plans and develops projects involving airports, overseeing their construction, Air Traffic Organization — primary duty is to safely and efficiently move air traffic within the National Airspace System. ATO employees manage air traffic facilities including Airport Traffic Control Towers, Aviation Safety — Responsible for aeronautical certification of personnel and aircraft, including pilots, airlines, and mechanics. Commercial Space Transportation — ensures protection of U. S. assets during the launch or reentry of commercial space vehicles, the FAA is headquartered in Washington, D. C. as well as the William J. The newly created Aeronautics Branch, operating under the Department of Commerce assumed primary responsibility for aviation oversight, in fulfilling its civil aviation responsibilities, the Department of Commerce initially concentrated on such functions as safety regulations and the certification of pilots and aircraft. It took over the building and operation of the system of lighted airways. The Aeronautics Branch was renamed the Bureau of Air Commerce in 1934 to reflect its status within the Department. As commercial flying increased, the Bureau encouraged a group of airlines to establish the first three centers for providing air traffic control along the airways, in 1936, the Bureau itself took over the centers and began to expand the ATC system. The pioneer air traffic controllers used maps, blackboards, and mental calculations to ensure the separation of aircraft traveling along designated routes between cities. In 1938, the Civil Aeronautics Act transferred the civil aviation responsibilities from the Commerce Department to a new independent agency. The legislation also expanded the role by giving them the authority. President Franklin D. Roosevelt split the authority into two agencies in 1940, the Civil Aeronautics Administration and the Civil Aeronautics Board, CAA was responsible for ATC, airman and aircraft certification, safety enforcement, and airway development. CAB was entrusted with safety regulation, accident investigation, and economic regulation of the airlines, the CAA was part of the Department of Commerce. The CAB was an independent federal agency, on the eve of Americas entry into World War II, CAA began to extend its ATC responsibilities to takeoff and landing operations at airports. This expanded role eventually became permanent after the war, the application of radar to ATC helped controllers in their drive to keep abreast of the postwar boom in commercial air transportation. The approaching era of jet travel, and a series of midair collisions and this legislation gave the CAAs functions to a new independent body, the Federal Aviation Agency. The act transferred air safety regulation from the CAB to the new FAA, the FAAs first administrator, Elwood R. Quesada, was a former Air Force general and adviser to President Eisenhower

22.
Outer space
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Outer space or just space, is the void that exists between celestial bodies, including Earth. The baseline temperature, as set by the radiation from the Big Bang, is 2.7 kelvins. In most galaxies, observations provide evidence that 90% of the mass is in a form, called dark matter. Data indicates that the majority of the mass-energy in the universe is a poorly understood vacuum energy of space which astronomers label dark energy. Intergalactic space takes up most of the volume of the Universe, there is no firm boundary where outer space starts. However the Kármán line, at an altitude of 100 km above sea level, is used as the start of outer space in space treaties. The framework for international law was established by the Outer Space Treaty. This treaty precludes any claims of sovereignty and permits all states to freely explore outer space. Despite the drafting of UN resolutions for the uses of outer space. Humans began the exploration of space during the 20th century with the advent of high-altitude balloon flights. Earth orbit was first achieved by Yuri Gagarin of the Soviet Union in 1961, due to the high cost of getting into space, manned spaceflight has been limited to low Earth orbit and the Moon. Outer space represents an environment for human exploration because of the dual hazards of vacuum. Microgravity also has an effect on human physiology that causes both muscle atrophy and bone loss. In addition to health and environmental issues, the economic cost of putting objects, including humans. In 350 BCE, Greek philosopher Aristotle suggested that nature abhors a vacuum and this concept built upon a 5th-century BCE ontological argument by the Greek philosopher Parmenides, who denied the possible existence of a void in space. Based on this idea that a vacuum could not exist, in the West it was held for many centuries that space could not be empty. As late as the 17th century, the French philosopher René Descartes argued that the entirety of space must be filled, in ancient China, there were various schools of thought concerning the nature of the heavens, some of which bear a resemblance to the modern understanding. In the 2nd century, astronomer Zhang Heng became convinced that space must be infinite, extending well beyond the mechanism that supported the Sun, the surviving books of the Hsüan Yeh school said that the heavens were boundless, empty and void of substance

23.
Spaceflight
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Spaceflight is ballistic flight into or through outer space. Spaceflight can occur with spacecraft with or without humans on board, examples of human spaceflight include the U. S. Apollo Moon landing and Space Shuttle programs and the Russian Soyuz program, as well as the ongoing International Space Station. Examples of unmanned spaceflight include space probes that leave Earth orbit, as well as satellites in orbit around Earth and these operate either by telerobotic control or are fully autonomous. Spaceflight is used in exploration, and also in commercial activities like space tourism. Additional non-commercial uses of spaceflight include space observatories, reconnaissance satellites, a spaceflight typically begins with a rocket launch, which provides the initial thrust to overcome the force of gravity and propels the spacecraft from the surface of the Earth. Once in space, the motion of a spacecraft—both when unpropelled, some spacecraft remain in space indefinitely, some disintegrate during atmospheric reentry, and others reach a planetary or lunar surface for landing or impact. The first theoretical proposal of space using rockets was published by Scottish astronomer and mathematician William Leitch. More well-known is Konstantin Tsiolkovskys work, Исследование мировых пространств реактивными приборами, spaceflight became an engineering possibility with the work of Robert H. Goddards publication in 1919 of his paper A Method of Reaching Extreme Altitudes. His application of the de Laval nozzle to liquid fuel rockets improved efficiency enough for travel to become possible. He also proved in the laboratory that rockets would work in the vacuum of space, nonetheless and his attempt to secure an Army contract for a rocket-propelled weapon in the first World War was defeated by the November 11,1918 armistice with Germany. Nonetheless, Goddards paper was influential on Hermann Oberth, who in turn influenced Wernher von Braun. Von Braun became the first to produce modern rockets as guided weapons, von Brauns V-2 was the first rocket to reach space, at an altitude of 189 kilometers on a June 1944 test flight. At the end of World War II, von Braun and most of his rocket team surrendered to the United States, over the same period, the Soviet Union secretly tried but failed to develop the N1 rocket to give them the capability to land one person on the Moon. Rockets are the only means currently capable of reaching orbit or beyond, other non-rocket spacelaunch technologies have yet to be built, or remain short of orbital speeds. Spaceports are situated away from human habitation for noise and safety reasons. ICBMs have various special launching facilities, a launch is often restricted to certain launch windows. These windows depend upon the position of bodies and orbits relative to the launch site. The biggest influence is often the rotation of the Earth itself, once launched, orbits are normally located within relatively constant flat planes at a fixed angle to the axis of the Earth, and the Earth rotates within this orbit

Outer space, or just space, is the expanse that exists between celestial bodies, including Earth. Outer space is not …

This is an artist's concept of the metric expansion of space, where a volume of the Universe is represented at each time interval by the circular sections. At left is depicted the rapid inflation from the initial state, followed thereafter by steady expansion to the present day, shown at right.

In straight and level flight, lift (L) equals weight (W). In a banked turn of 60°, lift equals double the weight (L=2W). The pilot experiences 2 g and a doubled weight. The steeper the bank, the greater the g-forces.